U.S. Pat. No. 3,915,237 illustrates a fire suppressant system for use in a military vehicle. That system envisions one or more cylindrical pressure vessels arranged in upright orientations; the lower portion of each vessel is occupied by liquid fire suppressant material such as C Br F.sub.3 (tradename Halon 1301). The space above the liquid surface is occupied by an inert driver gas under pressure. Discharge of the suppressant material is through a remotely-controlled valve at the lower end of the pressure vessel.
The patented suppressant system requires that the pressure vessel be oriented in a vertical attitude; otherwise the inert pressurized driver gas would be apt to pass through the discharge valve, leaving some or all of the liquid suppressant still in the vessel. The present invention is directed to a fire suppressant system in which each pressure vessel can be oriented in a horizontal prone position without undesired loss of the pressurized driver gas. Use of the vessel in a prone position is desirable in low silhouette vehicles where space in the vertical direction may be very limited.
The vessel can be reoriented from a vertical position to a prone position by arranging a floating piston between the liquid fire suppressant material and the driver gas. As the discharge valve is opened the force of the driver gas is applied to one face of the piston; the piston in turn transmits the force to the liquid fire suppressant material for its discharge through the open valve. The piston has a sealed sliding fit with the inner surface of the cylindrical pressure vessel such that the driver gas is prevented from reaching the discharge valve.